A wide array of performance demands are put on the hoses used on fuel pumps, such as those used at gasoline filling stations and truck stops. For instance, such hoses must be strong, durable, flexible, resistant to organic solvents, resistant to volumetric expansion, offer a long service life, and have low permeability to gasoline. Such fuel hoses must also be capable of being coupled to fittings in a manner that prevents fuel from escaping.
There is currently a demand to further improve such hoses to make them even less permeable to fuels, such as gasoline, gasohol (gasoline which contains a significant amount of ethyl alcohol such as 10 percent or more), diesel, and biodiesel. This is because the fuel which migrates through the hose ultimately evaporates and escapes into the atmosphere which is an environmental concern. Accordingly, such hoses must comply with various standards imposed by the Environmental Protection Agency, the California Air Resources Board, and a host of other governmental authorities. However, improving the resistance of such hoses to permeation by fuel and particularly gasohol without compromising the needed physical and chemical characteristics of the hose has proven to be an extremely difficult task.